Safety ignition and control device



March 10, 1942.

G. HERBSTER 2,275,962

SAFETY IGNITION AND CONTROL DEVICE FOR BURNERS Filed Feb. 2, 1938 4Sheets-Sheet l INVENTORQ 1 GEORGE HERBSTER Ea ATTORNEY:

March 10, 1942. HER S ER 2,275,962

SAFETY IGNITION AND CONTROL DEVICE FOR BURNERS Filed Feb. 2, 1938 4Sheets-Sheet 2 I Q Fig.3

INVENTOR. v GEORGE HERBSTER G. HERBSTER 2,275,962 SAFETY IGNITION ANDCONTROL DEVICE FOR BURNERS March 10, 1942.

Filed Feb. 2, 1938 :4Sheets-Shee t s INVENTOR. GEORGE HERBSTER 2"ATTORNEY.

March 10, 1942. s. HERBSTER 2,275,962

SAFETY IGNITION AND CONTROL DEVICE FOR BURNERS I Filed Feb. 2, 1958 4Sheets-Sheet 4 INVENTOR. v GEORGE HER BSTE R,

I ATTORNEY.

Patented MarJO, 1942 SAFETY IGNITION AND CONTROL DEVICE .FORB .1:

George Herbster, Cleveland, Ohio, assignor to John fi Leonard, trustee,Cleveland, Ohio Application February 2, 193a, Serial No. 188,336

4 Claims. (cl. 158117.1)

This invention relates to a safety ignition and control device for afuel burner and particularly for a burner which is located so that it isnot readily accessible ,to or visible toanoperator.

For the purposes of illustration, the invention isdescribed hereininconnection with a service burner for a domestic gas range cooking oven,

its use in connection with other types of bumers-being readily apparentin theexemplary description and drawings.

Domestic gas range ovens constitute a fire and explosion hazard due tothe fact that the oven burner occasionally is extinguished by drafts ortemporary reduction in gas line pressure with a resultant accumulationof gas in the oven compartment; a

Attempts have been made to insure proper ignition of the oven serviceburner at all times by the provision of gas burning pilot burners whichoperate continuously. Since such pilot burners operate continuously,economy requires that they be adjusted to produce a very small flame.Consequently, the pilot itself is extinguished easily and cannot berelied upon as a complete safety ignition device for a service burner.

Again, since an oven service burner is not readily accessible andvisible to the operator of the range, it is not unusual for theoperator-to be unaware that the service'burner is not ignited until anexplosion occurs, or the kitchen or room is filled with a hazardousaccumulation of gas.

In domestic gas cooking ranges, thermostatic oven temperature controlshave been provided,

these controls being arranged to be set by a suitable indicating dial toprovide different degrees of temperature desired and to maintain the settemperature either byreducing the gas supply to the service burner or bytemporarily shutting ofi gas supply of the service burner. While thesecontrols are very desirable for the purposes intended, they increase theexplosion hazard due to the fact thatpsometimes after shutting off ofthe gas, or reduction of the supply to the bumer to such an extent thatthe burner becomes extinguished, the subsequent supply of gas does tion;

the usual manual gas cock for admission of fuel to the burner.

A correlative object is to supply ignition sparks in firing relation toa burner for re-igniting the burner automatically upon the burnerbecoming extinguished for anyreason; and, in the event the burner is not-re-lgnited with reasonable promptness, to block entirely the supply offuel thereto.

A more specific object is to provide a deVice for producing electricalsparks in firing relation to a burner, and thermally responsive meansoperated by the heat produced by the burner to cause cessation, of theproduction or such-sparks when the burner becomes ignited and has heatedthe thermally responsive means to a predetermined degree.

Another specific object is to provide a device for the purposesdescribed which employs a pilot v burner which is readilyaccessible andvisible to an operator of a range and which, as a condition precedent toits operation, necessitates the proper operation ofa burner remote fromit whereby it indicates at all times to the operator that the remoteburner is operating properly, or, that the remote; burner isextinguished. I

Other objects and advantages will become apparent fromthe followingspecification, wherein switch, showing the valve and switch in fullyopen position;

Figures 4 and 5 are enlarged cross-sectional views taken on planesindicated by the lines 4-6 and 5 -5, respectively, in Figure 2;

"Figure 6 is a view similar to Figure 1, illustrating a modification ofcertain parts of the inven- Figure l is a. plan view of the device andassociated burners illustrating the relation among the various parts foreffecting remote control of one of the burners, part of the device beingshown in section for cleamess in illustration;

burner consequent upon turning or opening of Figure 8 is a diagrammaticillustration of an electric circuit which may be used in connection withthe present invention.

Referring first to Figures 1 to 5, inclusive, the invention is shown inconnection with a service. burner and a pilot bilrner 2 arranged infiring relation to the service burner I. The admission of gas to theburners I and 2 is controlled initially by the usual rotatable stopcock'3 to which gas from a suitable main line is supplied through I agas inlet passage 4. The gas cock 3 is connected by a pipe 5 to thepilot burner 2 in a manner' such that when the gas cock 3 is turned toits on position gas is admitted to the pipe 5. Connected in the pipe 5between the gas cock 3 and pilot burner 2 is a pressure operatedauxiliary valve 6 which normally blocks the passage of gas through theline 5. The valve 6 has a duct 1 through which gas may flow from theportion of the pipe 5 which is adjacent the cock 3-to the portion of thepipe 5 which connects with the valve 6. Mounted in the valve 6 is alarge diameter piston 8 the under side of which is exposed to the fullpressure of the gas from the gas cock 3. The piston has a dependingneedle valve 9 which is rigid with the piston and normally seats in theinlet end of the duct 1 and blocks the passage of gas through the duct.The valve 9 is normally seated by gravity or a light spring (not shown).The piston 8 is operative when gas is admitted to'the valve Bfrom thegas cock 3 to be lifted by the gas pressure on the under side of thepiston 8 and thus to lift the needle valve 9 and connect the portions ofthe pipe 5 for admitting gas to the pilot burner 2.

Mounted on the piston 8 and movable therepositions.

connected to the body -at one sideof the valve seat and the pipe l8being connected to the body at the opposite side of the valve seat.Within the body is a valve disc 22 having a stem 23 which is mountedslidably in the body 20- for moving the valve disc 22 to open and closedMounted on the valve body is a supporting member having a tubular body24 disposed in coaxial relation to the stem 23. The body 24 -is open atboth ends and, at the end opposite with is a rod [0- of electricalinsulating material 8 lowers until the needle valve 9 seats in whichposition the contact H is moved out of connecting relation to thecontacts l2 and I3, thus opening the circuit therethrough. Accordingly,upon turning the gas cook 3 to open position-gas is not admitted to thepilot unless there is sufiicient pressure in the pipe 5 to raise thepiston 8. The piston and the pilot burner 2 are so related to the gasline pressure to be used therewith that the piston can rise and open thevalve and close the auxiliary switch only when there is sufiicient gaspressure to maintain the proper flow of gas to the pilot burner 2.Leadingfrom the gas cock 3 is'a pipe l5 by which gas is supplied for theservice burner I. The pipe I5 is connected to any suitable thermostaticoven temperature control 16 between the cock 3 and burner l. Beyond thecontrol 15, the pipe [5 is connected I to a thermostatically operatedstop valve, designated generally as I1. The pipe l5 enters the valve l1in such a manner that when the thermostatic control means thereof areunheated,

the valve is closed and prevents the flow of fuel to the service burnerI, but when the thermolstatic control means are heated, the valve 11 isopened and permits the flow of fuel to the service burner I through theextension pipe 18.

The valve 11 comprises a hollow body 20 having therein a valve seat 2|,the pipe l5 being from the valve body 20, has a yoke 25, Bimetalthermostatic levers 25 are pivotally connected by their ends to thefreeends of the arms of the yoke 25, respectively, and the opposite endsof the levers 26 are pivotally connected to the free ends of the arms ofthe yoke 21, respectively. The device is positioned so that thethermostatic levers 26 are in heating relation to the pilot burner 2,the configuration and positioning of the levers being such that uponheating of the levers by the burner 2, they move the yoke 21 away fromthe pilot burner 2 and toward the valve body 20,and upon cooling of thethermostatic levers 26, they move the yoke 21 toward the burner 2 andaway from the valve body 20 to the normal position illustrated inFigure 1. F

The tubular body 24, being open at both ends, permits relatively cooloutside air to be drawn therethrough so that the parts are protectedfrom heat and the thermostatic levers 'are cooled more readily andthereby rendered more quickly responsive when the device extends into aclosed oven compartment.

' Carried by the yoke 21 is a block 28 of electri cal insulatingmaterial having high di-electric properties. Secured by one of'its endsin the block 28 and extending axially of the tubular body 24 is a metalrod 29 which is preferably of the type of wire used for the sparkterminals in the ordinary automobile engine spark plug.

One end of the rod 29 provides a high capacity discharge spark terminaland is positioned sufficiently close to the burner as to provide a sparkgap across which a high frequency spark may jump from the end 'of therod 29 to the burner 2 when the burner is grounded and a high capacitycurrent is imposed upon the rod 29. This gap is preferably of a widthsuch that when the thermostatic levers 26 become heated by the burner 2and move the yoke 21 and, consequently, the rod 29 away from the burner2 a sufiicient degree to open the valve 11 an appreciable extent, as islater described herein, the gap between the end of the rod 29 and theburner 2 is increased to an amount beyond a predetermined maximumspark-gap and the spark cannot jump from the rod 29 to the burner 2 Highcapacity current is imposed upon the rod 29 through a metal ring 30which is supported by but electrically insulated from the tubular body24. The ring 30 very loosely accommodates the rod 29 and is connected bya suitable wire 3| to a source of high frequency curre t, care beingtaken to provide a sufficient amo nt of insulation, as illustrated,between thenvire 3t and the tubular body 24 to maintain the. spacing ofthewire 3| and the body 24 greater than thepredetermined maximum sparkgap which the high capacity current can jump.

Interposed between the outer end of the valve stem 23 and the adjacentend of the rod 29 is an interponent 32 of electrical insulatingmaterial. The interponent 32 is connected fixedly to the valve stem 23and to'the rod 29 so that the movement of the rod toward the valve body20 opens the valve and movement of the rod in the opposite directioncloses the valve. Secured to the interponent 32 for movement therewithis an annular flange 33 of insulating material. In order to providea-main switch for controlling the high capacity current, annulus or ringcontact 33 of suitable electrical conducting metal is carried on theouter periphery of the flange 33. At the opposite end of the interponent32 is a flange. 35, the flanges 33 and 35 providing opposed shouldersbetween which is slidably mounted on the interponent a switch element 36in the form of a sleeve of insulating material. Segmental contacts 31ofelectrical conducting material are carried on the element 36 and arearranged to be engaged by the ring contact 33 so that the ring contact33. bridges between the contacts 31' and completes the circuit from onecontact 31 to the other. The sleeve switch element 36 is of lessthickness than the'distance between the opposed shoulders of the flanges33 and 35 so that the sleeve switch element may slide endwise of theinterponent 32 a limited amount. Spring contact arms 33 are carried bythe 'body 23 and yieldably engage the segmental contacts 31 of theswitch element 36 forsupplyingelectrical current thereto. The spring"contacts 38normally yieldably resist endwise movement of the sleeveswitch element 36 in either direction. In the normal starting positionillus-' trated in Figure -1, the contacts 31 of the sleeve switchelement 33 are in contact with the conflange 35. Thereupon the contacts33 and 31 are moved with the rod-29 in the valve opening direction whileremaining in a predetermined maximum spaced relation to each other.Thus, upon initial movement of the rod 29-to'ward the valve body2il, themain switch provided by the contacts 33 and 37 is immediately opened.Con-.

tinued movement of the rod in the same direction increases the openingof the switch to a predetermined maximum amount, after which the entiremain switch moves with the rod 23 uponcontinued movement of the rod inthe same direction. Therefore, regardless of the, amount of movement ofthe rod 29 toward the body- 20 of the valve, only a predeterminedmaximum amount of movement of the rod in the opposite directionisnecessary to re-establishcontact between the contacts. 34 and thecontacts 31, and no appreciable delay can occur in re-establishing thespark if the burner 2 extinguished. Here itshould be noted that the endof the rod 23 nearest the burner 2 is so positioned that the'gapbetweenithe burner 2 and the rod 23 preferably exceeds the predeterminedmaximum spark gap only when the valve 23 iS fll11y open being connectedto the lit) volt alternating cur-' rent supplied by the wires 4|. Ifdesired, a

transformer may be interposed between the device 40 and the source ofalternating current 4|. Connected inseries with the spark-producingcircuit of the dewice 40, as is described more fully hereinafter, arethe spring contact arms 38, and their associated contacts 34 and 31, andalso the contacts i2 and I3 with their associated contact II. Thecircuit rendering the spark device 40 operative necessitates the closureboth of the contacts 34 and 31 with respect to each other and of thecontacts 82 and [3 by the contact H, Only when all of these' contactsare in circuit closing position is the device 40 rendered operative forproducing a high capacity discharge spark at the spark terminal end ofthe rod 29adjacent the pilot burner 2. If the contacts 36 and 32 areopen or-the contact II is'out of bridging relation to the contacts l2and I3, or both, no spark will be produced.

' Operation in contact, a circuit is'established for energizing the highcapacity discharge spark producing means 30 which, through the wire 3|,imposes a high capacity current on the rod 29. The high capacity currentcircuit is grounded at one side and due to the metal pipe connection ofthe pilot;

burner 2 it also forms a ground so that'a spark or continuous series ofsparks jump from the rod 29 to the burner 2 igniting the gas issuingtherefrom. Obviously, if the gas line pressure is below a predeterminedminimum, gas will not be admitted to the burner 2 and the controlcircuit will not be completed through the contacts I2 and i3.Consequently, neither the spark nor the flow of gas will occur.Upon-ignition of the pilot burner-2, however; the thermostatic levers 26become heated and move the rod 29 to break the contact between thecontacts 34 and 37 so that the spark from the terminal end of the rod 29to the burner 2 is arrested or discontinued.

In event the contact elements 34 and-31 become and thus is an additionalassurance that the spark will be discontinued and re-established,

if for some reason the switchodefined by the contacts 33 and 3? fails tooperate properly.

The source of high capacity current may be any suitable one of thevarious electrical de-l current and spark is indicated at 43; thisdevice therod will increase the gap at theburner 2 to such an extentthat no further. spark will be produced, thus providing an additionalsafety feature. This same movementof the rod, however, for breaking thecircuit between the contacts 33 and 37 opens the valve 22 and admits gasto the'service burner which is immediately ignited by the pilot burner2. In event "the pilot burner 2 becomes extinguished for any reason, thetherunostatic levers 26 cool, re-establishing the spark between the rod29 and the pilot burn r2 and thus re-igniting the burner 2. But if orsome reason the pilot burner 2 cannot be or is:not reigriited', thethermostatic levers 26 will cool to a .suficient degree toclose thevalve 22. Inthis connection, the follow-up "relation between the sleeveswitch element 36 andthe flange switch a short movement is necessarybefore contact is established between the contacts 34 and 31.

Ordinarily, it is desired at all times that the pilot and service burnercombination be used. However, if mere ignition is desired without thesafety features, it is apparent that the pilot .burner may be omittedand the rod 28 .used directly for the ignition of the service burner I.

Referring next to Figure 6, a combination similar to that abovedescribed is illustrated, except that the pipe line 50 leading to thepilot burner is connected to a valve 5| which corresponds to the valve20 instead of being connected directly to the gas cock 52. Referringfurther to Figure 6, there is shown a further modification in that aswitch 53 which is operated directly by the gas cock is used instead ofthe switch defined by contacts |2 and l3. In this form a contact member54 is arranged on and for rotation with the handle 55 of the gas cockfor closing acircuit through stationary contacts 56 when the gas cock isrotated to open position, the contacts 56 and 54 performing the samefunction as the contacts l2 and I3. Thus a circuit 'is establishedsimply by tuming'the handle 55 of the gas deck 52 *to on position. Thiscircuit is broken by opening of the contacts 51 and 58 when the pilotburner has become ignited.

Referring next to Figure '1, there is illustrated a safety ignitionsystem employing two thermostatically controlled valves each of which issimilar to that described in connection with Figure 1.-.' The particularmodification illustrated in Figure? is for use where it is desired toutilize a pilot which is located on the top of the range or "some otherpoint which is readily accessible and visible to the operator forcontrolling the operations of a burner which is remote from or concealedfrom an operator, for example, "in the ovenof the range. In Figure 7, anoven burner 8| and a second pipe 84 leads to the thermostaticallycontrolled valve of the oven burner. The pilotburner 6| is ignited by aspark produced by a rod or movable high frequency terminal 85 which isconnected to a source or means for producing the high capacity dischargespark in the same manner as the rod 28 heretofore described. Theconnection between the rod 65 with the high pressure source is throughthe electric wire 68 connected to a terminal 61 of the high capacitydischarge spark producing device or means 68. The rod 65 is connectedfor movement with a yoke 88 to the arms of which are connectedthermostatic levers 10. The op-' posite ends of the levers 18 areconnected to the free ends of a yoke H fixedly mounted on the body- 12of a control valve having a seat '|3 in the valve body 12. A cooperatingvalve disc -14 is carried by the rod and is'opened upon heating of thethermostatic levers IQ of the pilot burner 6|. Leading fromthe pilotburner gas supply line 63 is a branch line-15.which is connected withthe body 'IZ at one side of the valve seat 13. Leading from the valvebody 12 at theopposite side of the valve seat is a pipe line 16 whichleads to a tell-tale pilot burner H which may be located on top of therange or wherever it is readily accessible to the operator. It isapparent that before any gas can be admitted to the accessible pilotILthe pilot 8| first must be in operation and must have heated thethermostatic levers 18 to a suflicient degree to cause them to unseatthe valve disc 14. Arranged adjacent the pilot burner 11 is avalvedevice corresponding in all respects to the valve andthermostatically controlled device, including the rod 28 and valve 28,illustrated in Figure 1. The valve 88 is provided with a movable highcapacity terminal rod 8| arranged close to and in spaced relation fromthe burner 11 so as to provide a spark gap. The rod 8| is also connectedto the high capacity discharge terminal 81 of the high frequency device88 by a wire 82. -The spark gap between the movable terminal andtheburner 8| is normally less than the spark gap between the movableterminal 8| and the burner 11 so that when the. high capacity terminal6'! is energized, a spark will be produced only between the movableterminal 85 and the burner 8| rather than between the'terminal 8| andthe burner However; upon heating of th thermostatic levers 10, theterminal 65 is moved away from the burner 6| to a greater distance thanthe normal gap between the terminal 8| and burner 11. This occurs only.upon ignition and burning fdraoshort interval of the burner Gl.Consequently, a spark is first delivered to the burner 8| for ignitingthe gas and as soon as the gas is ignited, the spark is discontinued atthe burneril and established at-the burner 81, and, at the ,same time,the valve "is opened to admit gas to the pilot burner 11. Thereupon,thetelltale pilot burner TI. becomes ignited and the thermostatic levers'84 being inheating .relation to the burner 'Il, move the movableterminal 8| away from the burner 11 to such a degree thatthe spark canno longer jump the gap. Consequently, the spark is discontinued both atthe terminal 85 and at the terminal 8|. Concurrently with thisoperation'bf the movable terminal 8| by the thermostatic levers 84,however, the main control valve 85 is opened by the lever 84for-admitting gas to the serviceburner which is then ignited by thebumeril.

It is often desirable, however, as explained heretofore, that thehighpressure device be en.- tirely disconnected from the source of powerwhen it is not being used for producing the high capacity dischargesparks. In order to open the circuit-to the device 88, a switchmechanism including, contacts 81 and 88 and movable contacts 88 and 88are operative'ly associated with the rod 8|, these contacts andassociated switch elements-corresponding to the contacts and elements 33to 38, inclusive, of the switch described in connections with Figure 1.

Connected in series .with the switch composed of.the elements 81 to 88,inclusive, is an additional switch 8| which is operated to close thecircuit when the gas cook 62 is turned to on" position. The switch 8|comprises contacts 82 and 83 with an annular contact segment 84rotatable with the stop cock stem for bridging the Referringnext toFigure 8, the circuit and operating parts comprising one form of highcapacity discharge spark producing device are illustrateddiagrammatically. A 110 volt alternating current is supplied to thedevice from the 110 volt supply line 4|. One line of the 110 volt supplyis connected ,to a condenser I00, theopposite side of which condenser isconnected to a ground. The same line is also connected to a coil IOIwhich operates the vibrating reed I02, the reed being an electricalconductor. The reed makes and breaks contact with a contact a. I03. Awire I04 leads from the contact l03 and connects it to one terminal of aprimary winding I05.

' The opposite terminal of the primary winding I05 is connected to theopposite side of the 110 volt circuit by a wire I05. The two switchesheretofore described are connected in series with the last mentionedterminal of the coil I05, these establish the spark, it is necessarythat both of I the series connected switches be closed. Between theprimary winding I05 and the nearest one of the switches, the wire I 05is connected by a wire I01 to a condenser I08, the opposite side ofwhich is grounded. A wire I09 is con" nected to the wire I'I between theprimary wind-"- ing I and condenser I08 and to one side ofl thecondenser IIO, the opposite side of which condenser IIO being connectedto that terminal of the coil I0l whichis between the coil IM and thevibrating reed I02, as indicated at III.- A secondary winding H2 ispositioned-in inductive relation to the primary winding I05 and oneterminal of the secondary winding H2 is connected to the terminal of thecoil I05 between the coil I05 and the contact I03. The winding H2 isprovided with a metal pole piece 3 to which is connected the wire 3I.The other terminal of the'secondary winding H2 is connected to the metalpole piece H3. The wire 31 is connected to the movable terminal or rod29, which,

first burner terminal is inoperative until the gap of the second pilotburner terminal is made greater than the gap of the first, thermostaticmeans in heating relation to the pilot burners respec- 5 tively andoperated when heated to. move the associated terminals away from theassociated pilot burners and beyond said maximum, valve means operatedby the thermostat means of the second pilot burner when the lastmentioned thermostat means is heated to admit fuel to the first pilotburner, and valve means operated by the thermostat means of the firstpilot burner when the last mentioned thermostat means isheated to admitfuel to the service burner, whereby the readily accessible first pilotburner cannot be ignited for admitting fuel to the service in thecircuit arranged to close the same, said switch having a contact fixedlyconnected to a movable member of the thermostat and another contacthaving a limited lost-motion connection with the movable member of thethermostat, and

- means resisting but up: preventing movement of the second mentionedcontact away from the first, whereby the circuit can be broken by ini:tial movement of the movable member in onedirection and re-estalilishedupon taking up of the lost motion by movement of the member in theopposite direction irrespective of the extent of movement of the memberin the first direcemitted therefrom and cooperating ground conductormeans for the terminals; a single source of high potential currentconnected electrically to both terminals, both terminals being insparkin turn, through.the spark gap, completes the capacity dischargespark device may be-used.

In this modification it is apparent that at all times the readilyaccessible tell-tale pilot is burning and the operation of the ignitingpilot or remote burner and the service burner is assured and properoperation of the latter is indicated;

Having thus described my invention, I claim:

1. An ignition device for a service burner com-' prising a pilot burnerreadily accessible to an operator, means for admitting fuel to saidpilot burner, a second pilot burner'remote from the first pilot burnerand in firing relation to the service burner, electric spark terminalsassociated with the pilot burners, respectively, each terminal beingspaced from its associated pilot burner and providing a spark gap forigniting its associated pilot burner when the spark gap is less than apredetermined maximum, high frequency electric spark producing meansconnected to said terminals, the spark gap for the second pilot burnernormally being less than that for th first pilot' burner and both gapsnormally delivering relation to their respective, ground means, oneterminal being initially spaced closer to its ground means than is theother terminal to its ground means so that the former only is initiallyeffective to deliver spark, a thermostat motor in heat-receivingrelation to one of the burners and connected to said one spark terminalin amanner to separate said one terminal from its ground means a greaterdistance than the spacing of the other terminal from its ground beingless than the maximum, whereby the sec-,

means whenthe thermostat motor is heated'b said burner, whereby gas willbe ignited at said other "burner only after gas has been ignited at saidone of the burners.

4."A gas ignition and control system for a service burner comprising twopilot burners, one pilot burner in igniting relation to the serviceburner and the other pilot burner remote from the service burner,thermally responsive-means operatively associated with said one pilotburner for controlling flow of gas to said other pilot burner, a valvefor controlling the fiow of gas to the service burner, thermallyresponsive means operatively associated with said other pilot burn erfor operating said valve, and igniting means in igniting relation tosaid'other pilot. burner and rendered operative consequent uponpredetermined heating of the, thermally responsive means of said onepilot burner for igniting the said other pilot-burner.

GEORGE HERBSTER.

